Desalination of masonry structures: Fine tuning of pore size distribution of poultices to substrate properties

Desalination is a relatively new intervention in the field of conservation of architectural heritage. Especially the desalination of immovable objects, such as masonry structures, is still a trial-error practice. In the field, different desalination materials and methods are used, sometimes with unsatisfactory results. Better understanding of the desalination process is needed in order to support the conservator with clear guidelines for choosing a suitable desalination material and method. The research presented in this paper constitutes the first step towards the development of a modular system of poultices, which can be adapted, i.e. fine-tuned to different types of substrates. Starting point is to make use of advection, i.e. the transport of salt ions with water flow. This transport mechanism is faster than diffusion and the application on immovable objects is relatively easy. In order to optimize salt extraction, a poultice working by advection should have smaller pores than the substrate. Starting from this principle the pore sizes of different desalination materials (sand, cellulose, kaolin and bentonite) mixed in different proportions, have been measured. Interesting results were obtained, showing that the desalination materials commonly used in the field are often not the most suitable ones. On the basis of the results, recipes for poultices, adapted to a specific substrate, can be formulated.     

Practical Applications as a Source of Credibility: A Comparison of Three Fields of Dutch Academic Chemistry

In many Western science systems, funding structures increasingly stimulate academic research to contribute to practical applications, but at the same time the rise of bibliometric performance assessments have strengthened the pressure on academics to conduct excellent basic research that can be published in scholarly literature. We analyze the interplay between these two developments in a set of three case studies of fields of chemistry in the Netherlands. First, we describe how the conditions under which academic chemists work have changed since 1975. Second, we investigate whether practical applications have become a source of credibility for individual researchers. Indeed, this turns out to be the case in catalysis, where connecting with industrial applications helps in many steps of the credibility cycle. Practical applications yield much less credibility in environmental chemistry, where application-oriented research agendas help to acquire funding, but not to publish prestigious papers or to earn peer recognition. In biochemistry practical applications hardly help in gaining credibility, as this field is still strongly oriented at fundamental questions. The differences between the fields can be explained by the presence or absence of powerful upstream end-users, who can afford to invest in academic research with promising long term benefits.     

Virology Experts in the Boundary Zone Between Science,Policy and the Public: A Biographical Analysis

This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy and public debate. A biographical-narrative approach is used to analyse the roles played by the virologists Albert Osterhaus, Roel Coutinho and Jaap Goudsmit in policy and public debate. These figures were among the few leading virologists visibly active in the Netherlands during the revival of infectious diseases in the 1980s. Osterhaus and Coutinho in particular are still the key figures today, as demonstrated during the outbreak of novel influenza A (H1N1). This article studies the various political and communicative challenges and dilemmas encountered by these three virologists, and discusses the way in which, strategically or not, they handled those challenges and dilemmas during the various stages of the field’s recent history. Important in this respect is their pursuit of a public role that is both effective and credible. We will conclude with a reflection on the H1N1 pandemic, and the historical and biographical ties between emerging governance arrangements and the experts involved in the development of such arrangements.     

The practical paradox of technology: The influence of communication technology use on employee burnout and engagement

Technological advancements in the workplace frequently have produced contradictory effects by facilitating accessibility and efficiency while increasing interruptions and unpredictability. We combine insights from organizational paradoxes and the job demands–resources model to construct a framework identifying positive and negative mechanisms in the relationship between communication technology use (CTU) and employee well-being, operationalized as work engagement and burnout. In this study of Dutch workers, we demonstrate that CTU increases well-being through positive pathways (accessibility and efficiency) and decreases well-being through negative pathways (interruptions and unpredictability). We highlight the importance of (1) investigating CTU resources and demands simultaneously to grasp the relationship between CTU and employee well-being, and (2) considering CTU's downsides to successfully implement new communication technologies and flexible work designs.     

Core‐explore‐more: A structure for planning enrichment activities

A framework for planning enrichment activities within a self‐contained classroom is described through the structure of Core‐Explore‐More. At the Core level, activities systematically introduce students to concepts, generalizations and basic skills related to an important curriculum theme. Explore activities allow follow‐up experiences for those students who have been excited and motivated by what they have done at the core level. More activities require greater commitment and individual student initiative because of their specialization.     

Using Workflow for Projects in Higher Education

The WWW is increasingly used as a medium to support education and training. A course at the University of Twente in which groups of students collaborate in the design and production of multimedia instructional materials has now been supported by a website since 1995. Workflow was integrated with other components in the website to investigate whether workflow can help instructors and students to have a better overview of group progress. Our evaluation shows that the introduction of workflow does provide added value. Another outcome of the experiment is that the transfer of a business application (workflow) into the educational domain has highlighted some differences and similarities between educational and business processes. This article explores some of these issues as highlighted by the application of workflow in education.     

The evaluation of peer-review quality

This paper discusses the role of peer review in the decision-making processes of scientific journals. It outlines the objectives of peer review and some of the problems. It then goes on to describe research into the quality of peer review, in particular the BMJ's programme of research to date, the results obtained, and consequent changes in practice. It also looks briefly at future possibilities for research into the peer-review process.